The invention relates to a semiconductor circuit with at least two field effect transistors united in a semiconductor crystal with insulated control electrodes and coincident conductivity type of their source and sink zones which are surrounded in common by a semiconductor area of the opposite conductivity type. A generator exhibiting an oscillator and a control loop with a threshold voltage detector is provided for generating an auxiliary voltage V.sub.BB to be applied between the semiconductor area of the opposite conductivity type and ground. This auxiliary voltage is applied to the parts of the semiconductor circuit to be loaded via a pump circuit provided at the output of the generator.
Such a semiconductor circuit is discussed in "Electronics," Sept. 16, 1976, page 42 and in "1976 IEEE International Solid-State Circuit Conference, " pages 56/57, both incorporated herein by reference. In these semiconductor circuits, the substrate bias generator is integrated, is likewise realized in MOS technology, and pumps electric charges into the area of the opposite conductivity type surrounding the current-bearing zones of the field effect transistors generally designated as a substrate. A very narrow range of fluctuation of access time and power consumption from chip to chip results from the regulation of the pump process, since the effects of fluctuations of the process parameters, temperature and supply voltage are reduced.
In the known arrangements, the pump circuit is formed by means of a capacitance with a MOS-diode connected to the substrate and via which electric charge is pumped into the substrate during the operation of the generator. The capacitance is driven by means of an oscillator with an amplifier. However, as a result of the substrate leakage current, the bias voltage V.sub.BB to ground conditioned by the charging of the substrate again decreases until the occurrence of the respectively next falling edge of the oscillator pulse.